Prof Niel J le Roux

Professor

University of Stellenbosch

Private Bag X1, Matieland

7602, South Africa

Tel:         +(27) 21 808 3243

Fax:        +(27) 21 808 3830

e-mail:     njlr@sun.ac.za

Obtained  MSc degrees in Experimental Psychology (Cambridge 1970), Mathematical Statistics (UNISA 1975), Geography (US 1990) and a PhD in Mathematical Statistics at UNISA in 1979.  Receiver of  the Rector’s Award for Excellence in Teaching (1994) and for Excellence in Research (2005).

National Research Foundation of South Africa

Rated by the National Research Foundation (NRF) as an established researcher, October 2004.

Present Teaching Subjects

Mathematical Statistics 318 and 354

Introduction to R / S-PLUS (Postgraduate)

Multivariate statistical analysis (Honours)

Advanced multivariate statistical analysis (Masters)

Bootstrap and other resampling techniques (Masters)

Multi-dimensional scaling (Masters)

Present Research Interests

• Biplot methodology and graphical display of multidimensional data, multivariate statistical  analysis,  discriminant analysis, principal componant analysis, statistical modelling, classification techniques, computer intensive methods.

• Promoter/Study leader for various PhD and Magister projects

Book Contributions

• Hail Day Frequency, pp 251 – 252 in Roland E Schulze, 1997. South African Atlas of Agrohydrology and -Climatology.

Publications in Journals (all downloads must be authorized first by the author or the Journal)

• Steel, SJ & Le Roux, NJ.   1987.  A reparameterisation of a bivariate gamma  extension. Communications in Statistics, 16, 293 - 305. (Download PDF)

• Steel, SJ & Le Roux, NJ.   1989.  A class of compound distributions of the reparameterised bivariate gamma extension. S.A. Statistical Journal, 23, 131 - 142. (Download PDF)

• Le Roux, NJ & Olivier, P.  1992.  Diskriminantanalise en trosanalise as beskrywende tegnieke van finansiële mislukking. Bedryfsdinamika,  1, 55 - 66.

• Le Roux, NJ & Olivier, J.   1996.  Modelling hail frequency using a generalized additive interactive technique.  S. A. Geographical Journal, 78, 7 - 12. (Download PDF)

• Le Roux NJ,  Steel SJ & Louw N.   1997.  Variable selection and error rate estimation in discriminant analysis. Journal of Statistical Computation and  Simulation, 59, 195 – 219. (Download PDF)

• Louw N, Steel SJ & Le Roux NJ.   1998.  A comparison of the classification performance of two approaches to polychotomous logistic regression. South African Statistical Journal,  32, 145 – 168. (Download PDF)

• Bloom JZ, Lambrechts IJ, Le Roux NJ.  1998.  Distinguishing between capital intensive and labour intensive enterprises  listed in the industrial sector of the JSE.  Management Dynamics, 7,  39 – 68. (Download PDF)

• Gardner S, Baard EHW & Le Roux NJ.  1999.  Estimating the detection robability of the geometric tortoise, Psammobates geometricus, under field conditions. South African Journal of Wildlife Research, 29,  62 –  71. (Download PDF)

• Bloom JZ, Lambrechts IJ, Le Roux NJ.  2000.  Patterns in financial performance indicators of capital and labour intensive enterprises during an upswing and  a decline in the economic cycle.  SA Journal of Accounting Research, 14, 59 – 90. (Download PDF)

• Steel SJ,  Louw n & le roux nj.  2000. a comparison of the post selection error rate behaviour of the normal linear and quadratic discriminant rules. Journal of Statistical Computation and  Simulation, 65, 157 – 172. (Download PDF)

• Burden m,  gardner s, le roux nj & swart jpj.  2001.  Ou-Kaapse meubels en stinkhoutidentifikasie:  Moontlikhede met kanoniese veranderlike-analise en bistippings.  SA Tydskrif vir Kultuurgeskiedenis, 15, 50 – 73. (Download PDF)

• Erasmus PD, Lambrechts IJ, Le Roux NJ & Gardner S. 2001.  The use of biplots to interpret multivariate data:  Measuring capital intensity. Management Dynamics: Contemporary research, 10(4),  48 – 73. (Download PDF)

• Bloom JZ, Lambrechts IJ & Le Roux NJ.  2002.  The behaviour of financial ratios for capital and labour intensive enterprises during the economic cycle. Journal for Studies in Economics and Econometrics, 26(1), 51 – 70. (Download PDF)

• Van der Berg S, Wood LC  & Le Roux NJ.  2002.  Differentiation in black education. Development Southern Africa, 19, 289 – 306. (Download PDF)

• Wurz S, Le Roux NJ, Gardner S & Deacon HJ. 2003. Discriminating between the end products of the earlier Middle Stone Age sub-stages at Klasies River using biplot methodology. Journal of Archaeological Science, 30, 1107 – 1126. (Download PDF)

• Erasmus PD, Lambrechts IJ, Gardner S & Le Roux NJ.  2003. The evaluation of traditional and value-added measures of capital intensity, Management Dynamics, 12, 12 – 23. (Download PDF)

• De Villiers JU, Hamman WD, Joubert C & Le Roux NJ.  2003. Earnings per share and cash flow per share as determinants of share value:  Tests of significance using the bootstrap with Demsetz’s method. Journal for Studies in Economics and Econometrics, 27(1), 95 – 125. (Download PDF)

• Le Roux NJ, Gardner S & Olivier P.  2003. Biplots for displaying multidimensional financial performance data graphically.  South African Journal of Accounting Research, 17(1), 41 – 64. (Download PDF)

• Aldrich C, Gardner S & Le Roux NJ. 2004. Monitoring of metallurgical process plants by using biplots. American Institute for Chemical Engineering Journal, 50(9), 2167 – 2186. (Download PDF)

• Joubert C, Le Roux NJ De Villiers JU & Hamman WD.  2004. Earnings per share and cash flow per share as determinants of share prices in different phases of the economic business cycle as measured by the bootstrap applied to Demsetz’s method. Journal for Studies in Economics and Econometrics, 28(1), 89 – 118. (Download PDF)

• Bothma A, Botha HL & Le Roux NJ.  2004. School results and access test results as indicators of first year performance at university.  ORiON, 20(1), 73 – 88. (Download PDF)

• Le Roux NJ, Bothma A & Botha HL.  2004.  Statistical properties of indicators of first-year performance at university. ORiON, 20(2), 166 – 178. (Download PDF)

• Gardner S & Le Roux NJ. 2005. Extensions of biplot methodology to discriminant analysis. Journal of Classification, 22, 59 – 86. (Download PDF)

• Le Roux NJ, Hamman WD, De Villiers JU & Joubert C.  2005.  The influence of the nature of an enterprise’s activities on earnings per share and cash flow per share as determinants of share prices. Journal for Studies in Economics and Econometrics, 29(1), 61 – 81. (Download PDF)

• Gardner S, Le Roux NJ & Aldrich C.  2005.  Process data visualisation with biplots.  Minerals Engineering, 18, 955 – 968. (Download PDF)

• Wurz S, Van Peer P, Le Roux NJ, Gardner S & Deacon HJ.  2005.  Continental patterns in stone tools: a technological and biplot-based comparison of early Late Pleistocene assemblages from northern and southern Africa.  African Archaeological Review.  22(1),  1 – 24. (Download PDF)

• Le Roux NJ, Gardner S & Aldrich C. Biplot analysis of process systems.  2005. The Transactions of the South African Institute of Electrical Engineers.  96(4),  253 – 258. (Download PDF)

• Gardner S & Le Roux NJ. Graphics and visualisation in practice: 2005. Analysing your multivariate data as a pictorial: a case for applying biplot methodology? International Statistical Review. 73(3), 365 – 387. (Download PDF)

• Gardner S, Le Roux NJ, Rypstra T & Swart JPJ.  2005. Extending a scatterplot for displaying group structure in multivariate data. ORiON, 22(2), 111 – 124. (Download PDF)

• Gardner S, Gower JC & Le Roux NJ. 2006. A synthesis of canonical variate analysis, generalised canonical correlation and Procrustes analysis. Computational Statistics and data Analysis, 50(1), 107–134. (Download PDF)

• Le Roux NJ & Gardner S. 2006. A biplot-based approach to discriminant analysis with categorical variables in the presence of reversals. The South African Statistical Journal. 40(1), 1–31. (Download PDF)

• Arnold, G, Gower, JC, Gardner-Lubbe, S & le Roux, NJ. 2007. Biplots of free-choice-profile data in Generalized Orthogonal Procrustes Analysis.  Journal of the Royal Statistics Society, Series C: Applied Statistics, 56, 445 – 458. (Download PDF)

• Gardner-Lubbe S, Le Roux NJ & Gower JC. 2008. Measures of fit in principal component and canonical variate analyses. Journal of Applied Statistics, 35(9-10), 947 – 965. (Download PDF)

• Walters IS & Le Roux NJ. 2008. Monitoring gender remuneration inequalities in academia using biplots. ORiON, 24(1), 49 – 73. (Download PDF)

• Van Heerden A, Le Roux NJ, Swart J,  Gardner-Lubbe S & Botha A. 2008. Assessment of wood degradation by Pycnoporus sanguineus when co-cultured with selected fungi. World Journal of Microbiology and Biotechnology, 24(11), 2489 – 2497. (Download PDF)

• Du Plessis M, Le Roux, NJ, Gardner-Lubbe S, Swart JPJ & Rypstra T. 2008. The effect of Sirex noctilio infestation and fire damage on the chemical composition of South African-grown Pinus patula pulpwood. Southern Forests, 70(3), ?? – ??. (Download PDF)

   

Publications in Conference Proceedings (all downloads must be authorized first by the author or the Journal)

• Steel SJ, Louw N & Le Roux NJ.  1998. Variable selection and error rate estimation in normal linear and quadratic discriminant analysis. Proceedings of the 6^th Conference of the International Federation of Classification Societies. Rome. pp. 287 – 290.

• Bloom JZ, Lambrechts IJ & Le Roux NJ.  1998.  A preliminary analysis of differences in financial performance between capital intensive and non-capital intensive enterprises during an upswing and a decline in the economic cycle. FMA Kroniek 1998. Rotterdam. pp. 481– 512.

• Bloom JZ, Lambrechts IJ & Le Roux NJ. 2000. Behaviour patterns of financial performance indicators for capital and labour intensive enterprises covering individual years of the economic cycle. FMA-Kroniek. Redactic: Bonnet, MPB., Olink, H. & Spekle, RF. Rotterdam. pp. 251 –273.

• Erasmus PD, Lambrechts IJ, Le Roux NJ & Gardner S. 2000. Determining a method to measure the capital intensity for enterprises listed in the industrial sector of the Johannesburg Stock Exchange for the period 1989 to 1996. 2000. FMA-Kroniek. Redactic: Bonnet, MPB., Olink, H. & Spekle, RF. Rotterdam. pp. 275 – 295.

• Erasmus, PD, Lambrechts, IJ, le Roux, NJ & Gardner, S.  2001.  Measuring the capital intensity of enterprises listed in the industrial sector of the Johannesburg Stock Exchange:  The use of value added measures.  Proceedings of the tenth annual SAFA Conference convened at the University of Cape Town Graduate School of Business.

• Gardner S & Le Roux NJ. 2002.  Biplot methodology for discriminant analysis based upon robust methods and principal curves. Proceedings of the 8^th Conference of the International Federation of Classification Societies. Cracow, Poland. pp. 169 – 176. (Download PDF)

• Gardner S & Le Roux NJ. 2003a. Discriminant analysis with categorical variables: a biplot based approach. In Schader M, Gaul W & Vichi M (eds.) Between data science and applied data analysis: Proceedings of the 26^th Annual Conference of the Gesellschaft für Klassifikation. pp. 30 – 38. (Download PDF)

• Gardner S & Le Roux NJ. 2003b. Graphics and visualisation in practice: Biplots for exploring multidimensional reality. Bulletin of the International Statistical Institute, 54^th proceedings. Volume LX, Book 1, 270 – 273. (Download PDF)

• Gardner S, Le Roux NJ. & Aldrich C. 2003. Visualization of process data with biplots Proceedings of The 1^st  African Control Conference: AFCON 2003.  Cape Town, South Africa. (Download PDF)

• Gardner S & Le Roux NJ. 2004. Modified biplots for enhancing two-class discriminant analysis. In Banks D, House L, McMorris FR, Arabie P & Gaul W (eds.) Classification, clustering and data mining applications: Proceedings of the Meeting of the International Federation of Classification Societies (IFCS), Illinois Institute of Technology, Chicago, Springer-Verlag, New York, pp. 233 – 240. (Download PDF)

• Gardner S & Le Roux NJ. 2005. An identification biplot for detecting forgery. Bulletin of the International Statistical Institute, 55^th proceedings. Volume LX, Book 1, 270 – 273  (on CD). (Download PDF)

• Gardner S & Le Roux NJ. 2006.  Sub-species of Homopus Areolatus?  Biplots and small class inference with analysis of distance.  In Batagelj, V, Bock, HH, Ferligoj, A & Ziberna, A (eds). Data Science and Classification. Proceedings of the 10^th jubilee conference of the International Federation of Classification Societies, Springer-Verlag, Berlin, 221 – 228. (Download PDF)

• Gardner, S & le Roux, NJ. 2006.  Multidimensional visualisation of time series and the construction of acceptance regions in a PCA biplot.  In Rizzi, A & Vichi, M (eds).  Proceedings in Computational Statistics:  Compstat 2006. Physica-Verlag, Heidelberg, 829 – 836. (Download PDF)

International Conferences (all downloads must be authorized first by the author or the Journal)

• Louw N, Steel SJ, Le Roux NJ.  Selection of variables in discriminant analysis by means of crossmodel validation. 1996. Sydney International Statistical Conference.

• Louw N, Steel SJ & Le Roux NJ. Pre-test variable selection in discriminant analysis. 1997. The Second Scandinavian-Ukrainian Conference in Mathematical Statistics. Umea, Sweden.

• BLOOM JZ, LAMBRECHTS IJ, LE ROUX NJ. A preliminary analysis of differences in financial performance between capital intensive and non-capital intensive enterprises during an upswing and a decline in the economic cycle. 1998. Ninth FMA Congress,  Erasmus University,  Rotterdam.

• STEEL SJ, LOUW N, LE ROUX NJ.  Variable selection and error rate estimation in normal linear and quadratic discriminant analysis. 1998. The Sixth Conference of the International Federation of Classification Societies,  Rome.

• Gardner S & Le Roux NJ. 2003. Exploring differences and overlap between Middle Stone Age artefacts using multiple correspondence analysis and biplot methodology. CARME 2003: Correspondence analysis and related methods, Barcelona, Spain.

• Gardner-Lubbe, S, le Roux, NJ, Maunders, H & Patwardhan, S.  2007. Biplot Methodology in a Gene Expression Context.  Intelligent Systems in Molecular Biology Conference, 22–25 July 2007, Vienna, Austria. (Poster). (Download PDF)

• La Grange, AM, Gardner-Lubbe, S, Groenen, PJF & le Roux, NJ. 2007. Applying Unfolding in the Construction of Non-linear Biplot Trajectories. International Conference on Correspondence Analysis and Related Methods, 25 – 27 June 2007, Rotterdam, The Netherlands.

• Groenen, PJF, Gardner-Lubbe, S, Le Roux, NJ and La Grange AM. 2007.   Nonlinear Biplots with a Shortest Distance Interpretation, IMPS2007. International Meeting of the Psychometric Society, 10 – 13 July 2007. Tokyo, Japan.

• La Grange, AM, Gardner-Lubbe, S, Groenen, PJF & le Roux, NJ. 2007. Applying Unfolding in the Construction of Non-linear Biplot Trajectories. International Conference on Correspondence Analysis and Related Methods, 25 – 27 June 2007, Rotterdam, The Netherlands.

• Groenen, PJF, Gardner-Lubbe, S, Le Roux, NJ & La Grange AM. 2007. Nonlinear Biplots with a Shortest Distance Interpretation.IMPS2007.  International Meeting of the Psychometric Society, 10 – 13 July 2007. Tokyo, Japan.

• Gardner-Lubbe, S & Le Roux, NJ. 2008. Enhancing multivariate analyses in forestry and biopulping applications with biplot methodology. Abstracts for the XXIVth International Biometric Conference, 13-18 July 2008, Dublin, Ireland. International Biometric Society (http://ibc2008abstracts.tibs.org/). ISBN 978-0-9821919-0-3.

• Le Roux NJ & Gardner-Lubbe S. 2008. Geometrical considerations and biplots associated with canonical variate analysis involving two classes. HDM-2008. International Conference on Multivariate Statistical Modeling and High Dimensional Data Mining. 19-23 June 2008, Kayseri, Turkey.

• Lubbe S & Le Roux NJ. 2008. Biplots, bagplots, α-bags and more. RC33. 7th International Conference on Social Science Methodology. 1-5 September 2008, Naples (Italy).

• La Grange AM, Le Roux NJ & Lubbe S. 2008. Constructing and interacting with biplots: the BiplotGUI package for R. RC33. 7th International Conference on Social Science Methodology. 1-5 September 2008, Naples (Italy).

   

National Conferences (South African)

• 1979: The 1979-Conference of the S.A. Statistical Association, Cape Town. Le Roux NJ & Roux JJJ:  On the determination of bivector-variate and bimatrix-variate distributions from distributions of linear combinations of the random vectors and random matrices.

• 1983: The 1983-Conference of the S.A. Statistical Association, Durban. Le Roux NJ & Steel SJ:  Tweeveranderlike eksponensiaalverdelings en eksponensiaalekstensies.          

• 1983: The 1983-Conference of the S.A. Statistical Association, Durban. Steel SJ & Le Roux NJ:  Leeftydverdeling van ’n twee-komponent onderhoue sisteem.

• 1987: The 1987-Conference of the S.A. Statistical Association, Bloemfontein. Steel SJ & Le Roux NJ:  ’n Samegestelde gammaverdeling.

• 1990: The 1990-Conference of the S.A. Statistical Association, Cape Town. Le Roux NJ & Olivier J:  ’n Statistiese analise van bolug weerkundige data met spesiale verwysing na toestande wat met die voorkoms van hael in die Pretoria-Witwatersrandgebied geassosieer word.

• 1991: The 1991-Conference of the S.A. Statistical Association, Pretoria. Le Roux NJ & Olivier P:  Die gebruik van trosanalise en diskriminantanalise in die daarstelling van modelle om finansiële mislukking te voorspel.

• 1992: The 1992-Conference of the S.A. Statistical Association, Port Elizabeth. Le Roux NJ & Maritz JS: Finansiële Mislukkings-voorspellingsmodelle:  Logistiese regressie of diskriminant analise?

• 1993: The 1993-Conference of the S.A. Statistical Association, Pietermaritzburg. Le Roux NJ & Olivier J: Die modellering van hael met behulp van GAIM.

• 1994: The 1994-Conference of the S.A. Statistical Association, Berg-en-Dal. Le Roux NJ &  Erasmus PS:  Die houding van studente jeens ’n verpligte dienskursus in  Statistiek. 

• 1995: The 1995-Conference of the S.A. Statistical Association, Bloemfontein. Le Roux  NJ &  Olivier  J:  A statistical study of fog precipitation in mountainous areas in the Western Cape.

• 1995: The 1995-Conference of the S.A. Statistical Association, Bloemfontein. Louw N & Le Roux NJ:   The merits of discriminant analysis and logistic regression to distinguish under various circumstances between two groups.

• 1996: The 1996-Conference of the S.A. Statistical Association, Stellenbosch. Louw N, Steel SJ & Le Roux NJ:  Variable selection and error rate estimation in discriminant analysis by means of cross model validation.   

• 1996: The 1996-Conference of the S.A. Statistical Association,  Stellenbosch. Steel SJ, Louw N & Le Roux NJ:  Pre-test type variable selection in discriminant analysis.

• 1996: The 1996-Conference of the S.A. Statistical Association, Stellenbosch. Cilliers HM & Le Roux NJ: Pitfalls to keep in mind when using the c2 goodness-of-fit test for continuous data.

• 1997: The 1997-Conference of the S.A. Statistical Association, Dikhololo. Le Roux NJ & Gardner S:  Estimating the detection probability of geometric tortoises using designed experiments under field conditions.

• 1997: The 1997-Conference of the S.A. Statistical Association, Dikhololo. Louw N,  Steel SJ & Le Roux NJ:  A comparison of two approaches to polychotomous logistic regression.

• 1997: The 1997-Conference of the S.A. Statistical Association, Dikhololo. Steel SJ & Le Roux NJ:  The training of students in numerically intensive statistics.

• 1998: The Fifth Herpetological Association of Africa Symposium, Stellenbosch. Gardner S, Baard EHW & Le Roux NJ:   How many tortoises are there?

• 1998: The 1998-Conference of the S.A. Statistical Association, Midrand. Le Roux NJ & Gardner S:  An application of the EM algorithm to a left-censored statistical problem in industry.

• 1998: EBM Research Conference, Cape Technikon. Bloom JZ, Lambrechts IJ & Le Roux NJ:  An analysis of differences in financial performance between capital intensive and labour intensive enterprises during an upswing and a decline in the economic cycle.

• 1998: EBM Research Conference, Cape Technikon. Bloom JZ, Lambrechts IJ & Le Roux NJ:  Distinguishing between capital intensive  and labour intensive enterprises listed in the industrial sector of the JSE.

• 1999: The 1999-Conference of the S.A. Statistical Association, Durban.
  Van Blerk SP, Gardner S & Le Roux NJ:  S-PLUS Functions for Interactive Linear and Non-linear Biplots.

• 1999: The 1999-Conference of the S.A. Statistical Association, Durban. Gardner S & Le Roux NJ:  Applying Bootstrapping Techniques to PCA and CVA  Biplots.

• 2000: The 2000-Conference of the S.A. Statistical Association, Johannesburg. Gardner S & Le Roux NJ:  Discriminant analysis using principal curves in biplots.

• 2000: The 2000-Conference of the S.A. Statistical Association, Johannesburg. Gardner S & Le Roux NJ:  Biplot applications everywhere:  From quality control to stinkwood.

• 2001: Tenth annual SAFA Conference, Cape Town. Bloom JZ, Lambrechts IJ & Le Roux NJ.  Behaviour patterns of financial performance indicators for capital and labour intensive enterprises covering individual years of the economic cycle. 

• 2001: Tenth annual SAFA Conference, Cape Town. Erasmus PD, Lambrechts IJ, Le Roux NJ & Gardner S. Measuring the capital intensity of enterprises listed in the industrial sector of the Johannesburg Stock Exchange:  The use of value added measures.  

• 2001: The 2001-Conference of the S.A. Statistical Association, Goudini Spa.    
  Gardner S & Le Roux NJ.  Representing large multidimensional data sets:  Biplots bagplots and alpha-bags. 

• 2001: The 2001-Conference of the S.A. Statistical Association, Goudini Spa. Le Roux NJ & Gardner S.  Principal components and biplots in allometry: Determining subspecies in Homopus areolatus.

• 2002: The 2002-Conference of the S.A. Statistical Association, Pretoria. Gardner S & Le Roux NJ.  Applying robust techniques to biplot methodology.

• 2002: The 2002-Conference of the S.A. Statistical Association, Pretoria. Le Roux NJ & Gardner S.  Discriminant anlysis with binary variables: Biplots and the ‘reversal problem’.

• 2003: The 2003-Conference of the S.A. Statistical Association, Johannesburg. Gardner S & Le Roux NJ.  Application of biplotology in the two-class discriminant analysis problem. 

• 2003: The 2003-Conference of the S.A. Statistical Association, Johannesburg. Le roux NJ & Gardner S. Biplotology for comparing archaelogical artefacts from different sites.

• 2004:  Mineral Processing 2004, Somerset West. Gardner S, Le Roux NJ & Aldrich C. Better process monitoring with new generation biplots.

• 2004:  SA Statistiese Statistiese Vereniging Konferensie, Bloemfontein. Langner R & Le Roux NJ.  Summarising a distribution with self-consistent approximations.

• 2004:  SA Statistiese Statistiese Vereniging Konferensie, Bloemfontein. Le Roux NJ, Gardner S & Gower JC.  Using Procrustes analysis for a synthesis of canonical variate analysis and generalised canonical correlation analysis.

• 2004:   SA Statistiese Statistiese Vereniging Konferensie, Bloemfontein. Gardner S & Le Roux NJ.  An application of iterative estimation of effects in an experimental design and linear modelling context.

• 2005:   SA Statistiese Statistiese Vereniging Konferensie, Grahamstad. Le Roux NJ & Gardner S.  Extensions of biplot methodology for analysing group structure in multivariate data. 

• 2005:   SA Statistiese Statistiese Vereniging Konferensie, Grahamstad. Gardner S, Le Roux NJ & Gower JC.  Biplots for free choice profile data in generalised orthogonal Procrustes analysis.

• 2006: Gardner, S & le Roux, NJ.  Biplots in the exploratory analysis of gene expression arrays.  Annual South African Statistical Association Conference, 1 – 3 November 2006.

• 2006:  Le Roux, NJ & Gardner, S.  Statistical analysis of South African wood pulp data using biplots. Annual South African Statistical Association Conference, 1 – 3 November 2006, Stellenbosch.

• 2007:   Gardner-Lubbe, S, le Roux, NJ, Gower, JC, Maunders, H & Patwardhan, S. Measures of Fit for Biplots:  An Application in the Identification of Differentially Expressed Genes, Annual South African Statistical Association Conference, 31 October – 2 November, Johannesburg.

• 2007:   La Grange, AM, le Roux, NJ & Gardner-Lubbe, S. BiplotGUI: An Interactive Menu-driven Package for Biplots in R, Annual South African Statistical Association Conference, 31 October – 2 November, Johannesburg.

• 2007:   Le Roux, NJ, Gardner-Lubbe, S, la Grange, AM & Groenen, PJF. General method for obtaining smoothed non-linear biplot prediction trajectories, Annual South African Statistical Association Conference, 31 October – 2 November, Johannesburg.

• 2008: Le Roux, NJ & Lubbe, S. Optimal Canonical Variate Analysis Biplots when the Number of Groups is less than the Number of Variables, Annual South African Statistical Association Conference, 29 – 31 October, Pretoria.

• 2008: Lubbe, S., Le Roux, NJ &  Cilliers, R. A Biplot View on Socio-Economic Progress in South Africa 1994-2006.  South African Statistical Association Conference, 29 – 31 October, Pretoria.

   

Societies and Committees

• Member of the American Statistical Association

• Member of the South African Statistical Association

• Member of the Association for Mathematics Education in South Africa

• Fellow of the South African Statistical Association

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